Vacuum lifting device.



H. K. HITCHCOCK.

VACUUM LIFTING DEVICE.

APPLICATION FILED JULY 19, 1911.

2 SHEETS-SHEET I.

1% l\\\ Q l .3? 1e- WITNESS 7 INVENTOR.

ATTORNEYS.

H. K. HITCHCOCK.

VACUUM LIFTING DEVICE.

APPLICATION FILED LULY 19.19n.

1,294,108. Patent eb. 11, 1919.

2 SSHEET 2- WITNESS INVENTOR- ATTORNEYS.

HALBERT K. HITCHCOCK, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO PITTSBURGH PLATE GLASS COMPANY, A CORPORATION OF PENNSYLVANIA.

VACUUM LIFTING DEVICE.

Specification of Letters Patent. Patented Feb. 11, 1919.

Application filed July 19, 1917. Serial No. 181,468.

To all whom it may concern: I

Be it known that 1,;HALBEBT K. HITCH- COCK, a citizen of the United States, residing at Pittsburgh, in the county ofAllegheny and State of Pennsylvania, have'in vented certain new and useful Improvements in Vacuum Liftin Devices, of which the following is a speci cation.

. The invention relates to vacuum lifting or holding devices particularly designed for use in handling glass sheets but not limited to use in that relation. It has for its primary objects, the provision of an improved vacuum liftingcup, (1) which works independently of the other cups which are used with it and whose leakage will not affect the other cups,- (2) which has means for supporting the glass sheet inside the periphery of the block thus avoiding breakage incident to the air pressure, and (3) which is of simple durable construction and in which the wearing parts can be conveniently and cheaply replaced. One embodiment of the invention is illustrated in the accompanying drawings, wherein- Figure 1 is a vertical section through the device and Fig. 2 is a bottom plan view of the device of Fig. 1.

The device comprises a casing consisting of two parts 1 and 2 between which parts the diaphragm 3 of rubber or other suitable material is clamped, the halves of the casing being secured together by means of-the bolts 4; The lower edge oflthe part 2 is provided with the engaging lip 5 of rubber (I or other suitable material clamped in posi-- tion by means of the annular ring 6 secured by the bolts 7 The lower portion of the casing 2 is also provided with a plate 8 having the perforations 9, 10, 11, 12, shown in plan view in Fig. 2. 3

The inner edge of the diaphragm 3 is clamped between the plate 13 and the ring 14:, such rin being held in position by means of the olts 15. The plate 13 is also provided with a hollow stem 16 lying in the cylindrical portion 17 of the casing part 1. This stem carries a cap 18 screw-threaded into the stem and provided with a bufler sprin 19 adapted to engage the screw'cap 20. he diaphragm is normally held in the position illustrated, by means of the relatively strong coil spring 21, and a passage 22 is provided whereby air under pressure may be supplied to the chamber back of the diaphragm 3.

The plate 13 is provided withprojections adapted to fit down into the erforations 9,- 1 0, 1 1 and 12 when the diaphragm is forced into its: extreme forward position,

and the lower face of the plate is provided with a sheet 23 of relatively soft material which lies in front of the plate 8 when the diaphragm is in its extreme forward position.

In operation air is applied to the passage 22 caus1ng the diaphragm to move forward prior to the application of the engaging lip 5 to the sheet of material to be engaged,

such forward movement-of the diaphragm expelling the air from the cup on the front side of the diaphragm. The lip 5 is then glass or other material which is to be engaged, and the air pressure released from the passage 22 permitting the spring 21 to expand and carry the diaphragm to its rearmost position, as indicated in Fig. 1'. This produces a relatively high vacuum to the front of the diaphragm and gives a secure attacgment of the cup to the surface engage The provision of the perforated plate 8 with the corresponding projections on the plate 13 permits substantially all the air to be expelled from the interior of the cup on the forward movement of the diaphragm,

and the plate 8 is advantageous in that it provides a support for the sheet of material which-is engaged This is particularly important where the sheet is relatively thin or fragile. The soft surface 23 on the front face of the plate 13 avoids the danger of 'pressed against the surface of the sheet of breakage, such as might occur if the plate 8 were forced down sharply upon the sheet to be engaged. Since the vacuum is maintained by the spring each cup is independand engaging lip, may be easily replaced and at a relatively small cost, the main body air from the cup when such member is moved forward, fluid operated means for forcing the said member forward, and spring means for moving the said member to the rear.

2. In combination in a vacuum lifting or holding device, a cup comprising an engaging lip and a diaphragm for expelling air from thecup when the diaphragm is moved forward, means for applying fluid pressure for moving the diaphragm forward, and spring means for movingthe diaphragm to the rear. r

3. In combination in a vacuum lifting or holding device, a cup comprising a metal casing provided with an engaging lip at its forward edge, a diaphragm which divides the easing into two chambers, means for applying air pressure in the chamber be hind the diaphragm to move it forward, and spring means normally holding the diaphragm in its rearmost position.

4. In combination in a vacuum lifting or holding device, a cup comprising a metal casing provided with an engaging lip at its forward edge, a diaphragm which divides the easing into two chambers, means for applying air pressure in the chamber behind the diaphragm to move it forward, and a sprin also located in the chamber behind the diaphragmand adapted to move it to the rear.

5. In combination in a vacuum lifting or holdingdevice, a cup consisting of a twopart caslng, an engaging lip at the forward edge of one part of the casing, a diaphragm clamped at its edge between the parts of the casing and dividing it into two chambers, means for supplylng air pressure behind the diaphragm tomove it forward, and a spring for moving the diaphragm to the rear.

6. In combination in a vacuum lifting or holding device, a cupconsisting of a twopart casmg, an engaging lip at the forward edge of one'part of the casing, a diaphragm clamped at its edge between the parts of the casing and dividing it into two chambers, means for supplying air pressure behind the diaphragm to move it forward, and a spring for moving the diaphragm to the rear, the spring being located in the chamber behind the diaphragm.

7. In combination in a vacuum lifting or holding device, a casing provided with a perforated plate at its front side and an engaging lip projecting forward of the plate, a movable member for expelling air through said plate when moved forwardly, spring means for moving said member to the rear, and means for applying fluid pressure to overcome 'thespring means and move said member forward.

8. In combination in a vacuum lifting or holding device,.a casing provided with a perforated plate at its front side and an engaging lip rojecting forward of the plate, a movabl e member for expelling air through said plate when moved forwardly, said' member being provided with means for fitting into the perforations in the plate, spring means for moving said member to the rear, and means for applying fluid pressure to overcome the spring means andmove said member forward.

9. In combination in a vacuum lifting or holding device, a casing provided with a perforated plate at its front side and an engaging lip projecting forward of the plate, a diaphragm dividing the casing in two chambers and provided with projections for ffitting the perforations in said plate when the diaphragm is moved to forward position, spring means for moving the diaphragm' to the rear, and means for applying fluid pressure to the chamber to the rear of the diaphragm'to force it forward overcoming the spring means.

- 10. In combination in a vacuum lifting or holding device, a casing provided with a perforated plate at its front side and an engaging lip projecting forward of the plate, a movable member for expelling air through said plate when moved forwardly,

said member being provided with means for fitting into the perforations in the plate, relatively yielding engaging means carried by the faces of said last mentioned means, spring means for moving said member to the rear, and means for applying fluid '0' sure to overcome the spring pressure and move said member forward.

HALBERT K. HITOHOOOK. 

